Field of the Invention
The invention relates to a motor vehicle having an internal combustion engine and having an on-board power supply, for which at least one fuel cell module, which is operated with ambient air as oxidizing agent and also has a cooling circuit, is used.
In conjunction with motor vehicles, fuel cells systems are generally to be used to supply energy to an electric motor which is present as a motive drive of the vehicle. It has already become known from German published patent applications DE 197 03 171 A1 and DE 199 02 051 A1 to provide only the on-board power supply or parts of the on-board power supply via a fuel cell system in motor vehicles with internal combustion engines. This may take place as an alternative or in addition to the generator which is customarily present.
To operate the fuel cells, it is necessary to supply a fuel, for example a fuel gas, on the one hand, and an oxidizing agent, on the other hand. The oxidizing agent used may be the oxygen in the ambient air, which in particular when the motor vehicle is driving is effected by the air stream. Furthermore, coolants are usually also required.
European patent application EP 0 751 045 A2 describes a power-generating system for a vehicle with an internal combustion engine, in which there is a fuel cell system instead of a generator for generating electrical energy to operate electric consumers. Furthermore, U.S. Pat. No. 5,868,105 A discloses a cooling system with a temperature-controlled expansion vessel in which an engine is cooled by the expansion of a gas. A fuel cell system is not discussed in that document.
Furthermore, Japanese patent application JP 2000-303836 A discloses a hybrid system comprising a fuel cell drive and internal combustion engine for use in a vehicle, in which thermal energy from the engine circuit is used to start the fuel cells. For this purpose, the water circuit of the motor is diverted to the fuel cell drive. A device for cooling vehicle components comprising a coolant circuit which includes heat exchangers is described in European published patent application EP 0 638 712 A1. On the other hand, a cooling/heating circuit system specifically for vehicles with a fuel cell drive is described in detail in European published patent application EP 0 999 078 A1.